U.S. patent application number 16/592821 was filed with the patent office on 2020-01-30 for catheter and balloon catheter.
This patent application is currently assigned to ASAHI INTECC CO., LTD.. The applicant listed for this patent is ASAHI INTECC CO., LTD.. Invention is credited to Shogo HASE, Hiroshi ITO, Yuusuke SHIMIZU.
Application Number | 20200030573 16/592821 |
Document ID | / |
Family ID | 60570460 |
Filed Date | 2020-01-30 |
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United States Patent
Application |
20200030573 |
Kind Code |
A1 |
SHIMIZU; Yuusuke ; et
al. |
January 30, 2020 |
CATHETER AND BALLOON CATHETER
Abstract
A catheter includes a tubular inner layer, a reinforcing layer
disposed at least partially within the inner layer or on an outer
circumference of the inner layer, and an outer layer. The
reinforcing member is made of wound wires, each adjacent pair of
the wires having a gap therebetween. A bonding portion is disposed
in the gap of the reinforcing layer and includes an inner layer
protruding portion of the inner layer that extends into the outer
layer and is engaged with an outer layer protruding portion of the
outer layer that extends into the inner layer. This configuration
enlarges the area across which the outer layer and the inner layer
are bonded to each other within the gap of the reinforcing layer,
leading to a strengthened bond between the outer layer and the
inner layer.
Inventors: |
SHIMIZU; Yuusuke;
(Owariasahi-shi, JP) ; ITO; Hiroshi;
(Miyohshi-shi, JP) ; HASE; Shogo; (Sakura-shi,
JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
ASAHI INTECC CO., LTD. |
Seto-shi |
|
JP |
|
|
Assignee: |
ASAHI INTECC CO., LTD.
Seto-shi
JP
|
Family ID: |
60570460 |
Appl. No.: |
16/592821 |
Filed: |
October 4, 2019 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
15605047 |
May 25, 2017 |
10471232 |
|
|
16592821 |
|
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PCT/JP2016/079471 |
Oct 4, 2016 |
|
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15605047 |
|
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A61M 25/10 20130101;
A61M 2025/1045 20130101; A61M 25/005 20130101; A61M 2025/1079
20130101; A61M 25/104 20130101; A61M 25/001 20130101; A61M
2025/0183 20130101; A61M 25/0052 20130101; A61M 25/0108 20130101;
A61M 25/1002 20130101 |
International
Class: |
A61M 25/00 20060101
A61M025/00; A61M 25/01 20060101 A61M025/01; A61M 25/10 20060101
A61M025/10 |
Claims
1. A balloon catheter comprising: a tubular inner layer; a
reinforcing layer disposed at least partially within the inner
layer or on an outer circumference of the inner layer, the
reinforcing layer being made of wound wires, each adjacent pair of
the wires having a gap therebetween; and a balloon covering the
reinforcing layer, wherein a bonding portion is disposed in the gap
of the reinforcing layer, the bonding portion including an inner
layer protruding portion of the inner layer that extends into the
balloon and is engaged with a balloon protruding portion of the
balloon that extends into the inner layer.
2. The balloon catheter according to claim 1, wherein: the inner
layer protruding portion comprises a proximally extending portion,
an inwardly extending portion, and a distally extending portion
extending from the inner layer in that order, and the balloon
protruding portion comprises an inwardly extending portion, a
distally extending portion, an outwardly extending portion, and a
proximally extending portion extending from the balloon in that
order.
3. The balloon catheter according to claim 2, wherein the inner
layer protruding portion further comprises an outwardly extending
portion that terminates at the proximally extending portion of the
inner layer protruding portion.
4. The balloon catheter according to claim 1, wherein the bonding
portion includes at least two inner layer protruding portions that
extend into the balloon and are engaged with the balloon protruding
portion.
5. The balloon catheter according to claim 4, wherein the balloon
protruding portion is bifurcated and includes two outwardly
extending portions that engage with the two inner layer protruding
portions.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This is a Divisional of application Ser. No. 15/605,047
filed May 25, 2017, which in turn is a continuation of
PCT/JP2016/079471 filed on Oct. 4, 2016, the contents of which are
incorporated by reference herein in their entirety.
BACKGROUND
[0002] The disclosed embodiments relate to a medical device.
Specifically, the disclosed embodiments relate to a catheter and a
balloon catheter used for diagnosis or treatment of a stenosis
(also known as a stricture or obstruction) in a blood vessel or
digestive organ.
[0003] A stenosis that is formed within a blood vessel, a bile
duct, a pancreatic duct, or the like interrupts the flow of blood,
bile (biliary fluid), pancreatic juice, or the like, respectively.
A catheter is conventionally used for diagnosis or treatment of a
stenosis.
[0004] A typical catheter comprises a tubular inner layer, an outer
layer covering the outer circumference of the inner layer, and a
reinforcing layer arranged between and bonding together the inner
layer and the outer layer. In a catheter of this type comprising a
reinforcing layer interposed between an inner layer and an outer
layer, it is difficult to strengthen the bond between the inner
layer and the outer layer.
[0005] Techniques have been developed to solve this problem. One of
the techniques involves a catheter having a reinforcing layer with
a wavy contour, an inner layer having an outer surface that follows
the wavy contour of the reinforcing layer, and an outer layer
having an inner surface that follows the wavy contour of the
reinforcing layer (see Japanese Patent No. 4741151, for example).
Another one of the techniques involves a catheter having a
protruding portion that is disposed on an inner layer and that
protrudes through a gap in a reinforcing layer toward an outer
layer, and that extends in the distal direction to stick into the
outer layer (see International Publication No. WO 2015/012185, for
example).
[0006] However, in the catheter described in Japanese Patent No.
4741151, the irregularities provided on the outer circumference of
the inner layer and on the inner circumference of the outer layer
merely have a wavy contour and no other irregularities are
provided. In the catheter described in International Publication
No. WO 2015/012185, the protruding portion disposed on the inner
layer extends in only one direction: from the proximal end toward
the distal end. Therefore, there has been a problem that the outer
layer readily comes off the inner layer when the outer layer is
pulled in the distal direction due to the presence of a stenosis.
This problem is more likely to occur when the catheter is inserted
into a curved duct such as a blood vessel, a bile duct, or a
pancreatic duct, in which case the catheter bends and stress is
concentrated at the portion where the outer layer and the inner
layer are bonded to each other.
SUMMARY
[0007] The disclosed embodiments have been devised based on the
above circumstances, and an object of the disclosed embodiments is
to provide a catheter and a balloon catheter in which an outer
layer does not readily come off an inner layer when the outer layer
is pulled in the axial direction (in the distal direction and in
the proximal direction) or in the radial direction (outwardly).
[0008] The above problem is addressed by the structures discussed
below.
[0009] A catheter according to the disclosed embodiments includes a
tubular inner layer, a reinforcing layer disposed within the inner
layer or on an outer circumference of the inner layer, and a first
outer layer covering the reinforcing layer. The reinforcing layer
is made of wound wires, each adjacent pair of the wires having a
gap therebetween. At a first bonding portion disposed in a gap in
the reinforcing layer, a first inner layer protruding portion of
the inner layer extends into the first outer layer and is engaged
with a first outer layer protruding portion of the first outer
layer that extends into the inner layer.
[0010] This configuration enlarges the area across which the first
outer layer and the inner layer are bonded to each other within the
gap of the reinforcing layer, leading to a strengthened bond
between the first outer layer and the inner layer. And the first
bonding portion is anchored in the reinforcing layer, which reduces
the probability that the first outer layer will come off the inner
layer when the catheter bends (in which case the first outer layer
will be pulled in the axial direction (in the distal direction and
in the proximal direction)). In addition, the engagement between
the first inner layer protruding portion and the first outer layer
protruding portion at the first bonding portion can reduce the
probability that the first outer layer will come off the inner
layer when the first outer layer is pulled in the radial direction
(outwardly).
[0011] The catheter may further comprise a second outer layer
covering the outer circumference of the reinforcing layer, the
second outer layer being arranged distal to the first outer layer.
The second outer layer may be made of a material that is more
flexible than a material of which the first outer layer is made. At
a second bonding portion in the gap of the reinforcing layer, a
second inner layer protruding portion of the inner layer extends
into the second outer layer and is engaged with a second outer
layer protruding portion of the second outer layer that extends
into the inner layer. A degree of engagement at the second bonding
portion is higher than a degree of engagement at the first bonding
portion (more specifically, the engaging force between the second
inner layer protruding portion and the second outer layer
protruding portion at the second bonding portion is stronger than
the engaging force between the first inner layer protruding portion
and the first outer layer protruding portion at the first bonding
portion).
[0012] When the catheter is inserted into a peripheral section of a
blood vessel, a bile duct, a pancreatic duct, or the like (a
vessel), the distal side of the catheter bends to a great extent to
follow the curve of the vessel, and stress becomes concentrated at
the second bonding portion where the second outer layer made of a
flexible material is bonded to the inner layer. However, the high
degree of engagement between the second inner layer protruding
portion and the second outer layer protruding portion at the second
bonding portion (more specifically, the strong engaging force
between the second inner layer protruding portion and the second
outer layer protruding portion), as well as the enlarged area
across which the second outer layer and the inner layer are bonded
to each other in the gap of the reinforcing layer, strengthens the
bond between the second outer layer and the inner layer, which
reduces the probability that the second outer layer made of a
flexible material will come off the inner layer.
[0013] The catheter may be a balloon catheter. In this case, an
inner layer protruding portion extends into the balloon at a
bonding portion and is engaged with a balloon protruding portion of
the balloon that extends into the inner layer. This configuration
enlarges the area across which the balloon and the inner layer are
bonded to each other within the gap of the reinforcing layer,
leading to a strengthened bond between the balloon and the inner
layer. And the balloon is anchored in the reinforcing layer, which
reduces the probability that the balloon will come off the inner
layer when the balloon catheter bends (in which case the balloon
will be pulled in the axial direction (in the distal direction and
in the proximal direction)). In addition, the engagement between
the inner layer protruding portion and the balloon protruding
portion at the bonding portion can reduce the probability that the
balloon will come off the inner layer when the balloon is expanded
radially (outwardly). The engagement between the inner layer
protruding portion and the balloon protruding portion can also
allow a reduction in the thickness of the balloon while maintaining
the strength of the bond between the balloon and the inner layer,
facilitating insertion of the balloon catheter into the vessel.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 is an overall view of a catheter according to the
disclosed embodiments.
[0015] FIG. 2 is an expanded view of part A shown in FIG. 1.
[0016] FIG. 3 is a partial sectional view taken along line B-B
shown in FIG. 2, showing only the upper side of the catheter.
[0017] FIG. 4 is a partial sectional view of a catheter according
to the disclosed embodiments, viewed in the same manner as in FIG.
3.
[0018] FIG. 5 is a partial sectional view of a catheter according
to the disclosed embodiments, viewed in the same manner as in FIG.
3.
[0019] FIG. 6 is an expanded view of a catheter according to the
disclosed embodiments, viewed in the same manner as in FIG. 2.
[0020] FIG. 7 is a partial sectional view taken along line C-C
shown in FIG. 6, showing only the upper side of the catheter.
[0021] FIG. 8 is a partial sectional view of a catheter according
to the disclosed embodiments, viewed in the same manner as in FIG.
3.
[0022] FIG. 9 is an overall view of a balloon catheter according to
the disclosed embodiments.
[0023] FIG. 10 is a partial expanded view of part F shown in FIG.
9, showing only the upper side of the catheter.
[0024] FIG. 11 is a partial sectional view of a catheter according
to the disclosed embodiments, viewed in the same manner as in FIG.
3.
[0025] FIG. 12 is a partial sectional view of a catheter according
to the disclosed embodiments, viewed in the same manner as in FIG.
3.
DETAILED DESCRIPTION OF EMBODIMENTS
[0026] Referring to FIG. 1 to FIG. 3, a catheter 1 according to the
disclosed embodiments is described below. Throughout the figures,
the distal end (the front end) to be inserted into the body is
shown to the left hand side, and the proximal end (the rear end) to
be manipulated by a handler such as a doctor is shown to the right
hand side. FIG. 2 is an expanded view of part A shown in FIG. 1.
FIG. 3 is a partial sectional view taken along line B-B shown in
FIG. 2.
[0027] The catheter 1 is, for example, a catheter used for
diagnosis or treatment of a stenosis. As shown in FIG. 1, the
catheter 1 comprises a catheter shaft 60, a tip 70 bonded to a
distal end of the catheter shaft 60, and a connector 75 bonded to a
proximal end of the catheter shaft 60.
[0028] As shown in FIG. 2, the catheter shaft 60 comprises, in
order from inside in the radial direction, a tubular inner layer 10
having a reinforcing layer (coil body) 30 that is disposed therein,
and a first outer layer 40 covering the reinforcing layer (coil) 30
and the inner layer 10. The reinforcing layer 30 is made of wound
wires 20 with each adjacent pair of the wires 20 having a gap 25
therebetween. For easy understanding, FIG. 2 shows the catheter 1
with the first outer layer 40 partially removed.
[0029] The inner layer 10 is made of a resin and can accommodate a
guidewire or another catheter inserted thereinto. The resin
material constituting the inner layer 10 is not particularly
limited, but polytetrafluoroethylene (PTFE) is used for purposes of
this discussion.
[0030] The coil body as the reinforcing layer 30 is disposed in the
tubular inner layer 10. The coil body is made of the wires 20,
which are wound in the rightward direction toward the distal end.
As the material of the wires 20 constituting the coil body,
stainless steel (SUS304) is exemplified. However, the material is
not limited to stainless steel. The material may be a different
metal material such as tungsten or a Ni--Ti alloy, or a resin
material such as reinforced plastic (e.g., polyether ether ketone,
or "PEEK"), for example. Alternatively, the wires 20 constituting
the coil body may be wound in the leftward direction toward the
distal end.
[0031] The first outer layer 40 made of a resin is disposed on an
outer circumference of the reinforcing layer (coil body) 30 and
covers the inner layer 10 and the reinforcing layer (coil body) 30.
The resin material constituting the first outer layer 40 is not
particularly limited and a polyamide, a polyamide elastomer, a
polyester, or a polyurethane, for example, may be used.
[0032] Bonded to the distal end of the catheter shaft 60 described
above is the tip 70 made of a resin (see FIG. 1). The resin
constituting the tip 70 is not particularly limited, and may be a
polyurethane or a polyurethane elastomer, for example. The tip 70
may also contain a radiopaque powder. When the tip 70 contains a
radiopaque powder (such as a tungsten powder) in a content from
about 65 w % to about 90 w %, for example, a handler such as a
doctor can keep track of the exact location of the catheter 1
during coronary angiography.
[0033] As shown in FIG. 3, disposed in the gap 25 of the
reinforcing layer (coil body) 30 is a first bonding portion 50
where a first inner layer protruding portion 12 of the inner layer
10 extends into the first outer layer 40 and is engaged with a
first outer layer protruding portion 42 of the first outer layer 40
that extends into the inner layer 10.
[0034] The first inner layer protruding portion 12 is composed of a
proximally extending portion 13, an inwardly extending portion 14,
and a distally extending portion 15 extending from the inner layer
10 in that order. The first outer layer protruding portion 42 is
composed of an inwardly extending portion 43, a distally extending
portion 44, an outwardly extending portion 45, and a proximally
extending portion 46 extending from the first outer layer 40 in
that order.
[0035] The first bonding portion 50 enlarges the area across which
the first outer layer 40 and the inner layer 10 are bonded to each
other within the gap 25 of the reinforcing layer (coil body) 30,
leading to a strengthened bond between the first outer layer 40 and
the inner layer 10. The first bonding portion 50 is anchored in the
reinforcing layer (coil body) 30, which the probability that the
first outer layer 40 will come off the inner layer 10 when the
catheter 1 bends, causing the first outer layer 40 to be pulled in
the axial direction (in the distal direction and in the proximal
direction). In addition, the engagement between the first inner
layer protruding portion 12 and the first outer layer protruding
portion 42 can reduce the probability that the first outer layer 40
will come off the inner layer 10 when the first outer layer 40 is
pulled in the radial direction (outwardly).
[0036] Referring to FIG. 4, a catheter 2 according to the disclosed
embodiments is described below. Only differences from the catheter
1 shown in FIG. 3 are described below. In the catheter 2, an inward
surface of the coil body as the reinforcing layer 30 is buried in
an inner layer 10a, and an outward surface of the coil body as the
reinforcing layer 30 is buried in a first outer layer 40a. Disposed
in the gap 25 of the reinforcing layer (coil body) 30 is a first
bonding portion 50a where a first inner layer protruding portion
12a of the inner layer 10a extends into the first outer layer 40a
and is engaged with a first outer layer protruding portion 42a of
the first outer layer 40a that extends into the inner layer
10a.
[0037] The first inner layer protruding portion 12a is composed of
a proximally extending portion 13a, an inwardly extending portion
14a, and a distally extending portion 15a. The first outer layer
protruding portion 42a is composed of an inwardly extending portion
43a, a distally extending portion 44a, an outwardly extending
portion 45a, and a proximally extending portion 46a.
[0038] The first bonding portion 50a enlarges the area across which
the first outer layer 40a and the inner layer 10a are bonded to
each other within the gap 25 of the reinforcing layer (coil body)
30, leading to a strengthened bond between the first outer layer
40a and the inner layer 10a. The first bonding portion 50a is
anchored in the reinforcing layer (coil body) 30, which reduces the
probability that the first outer layer 40a will come off the inner
layer 10a when the catheter 2 bends, causing the first outer layer
40a to be pulled in the axial direction (in the distal direction
and in the proximal direction). In addition, the engagement between
the first inner layer protruding portion 12a and the first outer
layer protruding portion 42a can reduce the probability that the
first outer layer 40a will come off the inner layer 10a when the
first outer layer 40a is pulled in the radial direction
(outwardly).
[0039] Next, referring to FIG. 5, a catheter 3 according to the
disclosed embodiments is described below. Only differences from the
catheter 1 shown in FIG. 3 are described below. In the catheter 3,
the coil body as the reinforcing layer 30 is disposed on an outer
circumference of an inner layer 10b. Disposed in the gap 25 of the
reinforcing layer (coil body) 30 is a first bonding portion 50b
where a first inner layer protruding portion 12b of the inner layer
10b extends into a first outer layer 40b and is engaged with a
first outer layer protruding portion 42b of the first outer layer
40b that extends into the inner layer 10b.
[0040] The first inner layer protruding portion 12b is composed of
an outwardly extending portion 16, a proximally extending portion
13b, an inwardly extending portion 14b, and a distally extending
portion 15b. The first outer layer protruding portion 42b is
composed of an inwardly extending portion 43b, a distally extending
portion 44b, an outwardly extending portion 45b, and a proximally
extending portion 46b.
[0041] The first bonding portion 50b enlarges the area across which
the first outer layer 40b and the inner layer 10b are bonded to
each other within the gap 25 of the reinforcing layer (coil body)
30, leading to a strengthened bond between the first outer layer
40b and the inner layer 10b. The first bonding portion 50b is
anchored in the reinforcing layer (coil body) 30, which reduces the
probability that the first outer layer 40b will come off the inner
layer 10b when the catheter 3 bends, causing the first outer layer
40b to be pulled in the axial direction (in the distal direction
and in the proximal direction). In addition, the engagement between
the first inner layer protruding portion 12b and the first outer
layer protruding portion 42b can reduce the probability that the
first outer layer 40b will come off the inner layer 10b when the
first outer layer 40b is pulled in the radial direction
(outwardly).
[0042] Next, referring to FIG. 6 and FIG. 7, a catheter 4 according
to the disclosed embodiments is described below. Only differences
from the catheter 1 shown in FIG. 2 will be described. The catheter
4 comprises, in order from inside in the radial direction, an inner
layer 10c having a reinforcing layer (braid) 35 disposed therein,
and an outer layer 40c covering the reinforcing layer (braid) 35
(see FIG. 6). The reinforcing layer 35 is braided with a plurality
of first wires 20a and a plurality of second wires 20b, with each
adjacent pair of the first wires 20a and each adjacent pair of the
second wires 20b having a gap 25a therebetween. For easy
understanding, FIG. 6 shows the catheter 4 with the outer layer 40c
partially removed.
[0043] The reinforcing layer (braid) 35 is a net (mesh) braided
with the first wires 20a and the second wire 20b. The first wires
20a are wound in the rightward direction toward the distal end, and
the second wires 20b are wound in the leftward direction toward the
distal end. In the catheter 4, eight first wires 20a and eight
second wires 20b (i.e., 16 (=8.times.8) wires in total) are braided
over and under each other to form the reinforcing layer (braid)
35.
[0044] The first wires 20a and the second wires 20b constituting
the reinforcing layer (braid) 35 may be made of the same material
or different materials. The first wires 20a may be made of
tungsten, and the second wires 20b may be made of stainless steel
(SUS304), for example. Instead of a metal material, a resin
material (reinforced plastic, for example) may be used.
[0045] As shown in FIG. 7, disposed in the gap 25a of the
reinforcing layer (braid) 35 is a first bonding portion 50c where a
first inner layer protruding portion 12c of the inner layer 10c
extends into a first outer layer 40c and is engaged with a first
outer layer protruding portion 42c of the first outer layer 40c
that extends into the inner layer 10c.
[0046] The first inner layer protruding portion 12c is composed of
a proximally extending portion 13c, an inwardly extending portion
14c, and a distally extending portion 15c. The first outer layer
protruding portion 42c is composed of an inwardly extending portion
43c, a distally extending portion 44c, an outwardly extending
portion 45c, and a proximally extending portion 46c.
[0047] The first bonding portion 50c enlarges the area across which
the first outer layer 40c and the inner layer 10c are bonded to
each other within the gap 25a of the reinforcing layer (braid) 35,
leading to a strengthened bond between the first outer layer 40c
and the inner layer 10c. The first bonding portion 50c is anchored
in the reinforcing layer (braid) 35, which reduces the probability
that the first outer layer 40c will come off the inner layer 10c
when the catheter 4 bends, causing the first outer layer 40c to be
pulled in the axial direction (in the distal direction and in the
proximal direction). In addition, the engagement between the first
inner layer protruding portion 12c and the first outer layer
protruding portion 42c can reduce the probability that the first
outer layer 40c will come off the inner layer 10c when the first
outer layer 40c is pulled in the radial direction (outwardly).
[0048] The configuration of the reinforcing layer (braid) 35 of the
catheter 4 may be modified in the following ways: (i) as in the
catheter 2 shown in FIG. 4, an inward surface of the braid 35 as
the reinforcing layer may be buried in the inner layer 10c and an
outward surface of the braid 35 as the reinforcing layer may be
buried in the first outer layer 40c; or (ii) as in the catheter 3
shown in FIG. 5, the braid 35 as the reinforcing layer may be
disposed on the outer surface of the inner layer 10c.
[0049] Next, referring to FIG. 8, a catheter 5 according to the
disclosed embodiments is described below. Only differences from the
catheter 1 shown in FIG. 3 will be described. A proximal side D of
the catheter 5 comprises, in order from inside in the radial
direction, a tubular inner layer 10d having the reinforcing layer
(coil body) 30 disposed therein, and a first outer layer 40d
covering the reinforcing layer (coil body) 30. A distal side E of
the catheter 5 comprises, in order from inside in the radial
direction, the tubular inner layer 10d having the reinforcing layer
(coil body) 30 disposed therein, and a second outer layer 80
covering the reinforcing layer (coil body) 30.
[0050] The second outer layer 80 is made of a resin that is more
flexible than the resin constituting the first outer layer 40d. The
resin material constituting the second outer layer 80 is not
particularly limited and may be a polyamide, a polyamide elastomer,
a polyester, or a polyurethane, for example, as in the case of the
first outer layer 40d.
[0051] The proximal side D of the catheter 5 comprises, in the gap
25 of the reinforcing layer (coil body) 30, a first bonding portion
50d where a first inner layer protruding portion 12d of the inner
layer 10d extends into the first outer layer 40d and is engaged
with a first outer layer protruding portion 42d of the first outer
layer 40d that extends into the inner layer 10d. The distal side E
of the catheter 5 comprises, in the gap 25 of the reinforcing layer
(coil body) 30, a second bonding portion 50e where a second inner
layer protruding portion 12e of the inner layer 10d extends into
the second outer layer 80 and is engaged with a second outer layer
protruding portion 82 of the second outer layer 80 that extends
into the inner layer 10d.
[0052] The first inner layer protruding portion 12d is composed of
a proximally extending portion 13d, an inwardly extending portion
14d, and a distally extending portion 15d. The first outer layer
protruding portion 42d is composed of an inwardly extending portion
43d, a distally extending portion 44d, an outwardly extending
portion 45d, and a proximally extending portion 46d.
[0053] The second inner layer protruding portion 12e is composed of
a proximally extending portion 13e, an inwardly extending portion
14e, a distally extending portion 15e, and an outwardly extending
portion 16a. The second outer layer protruding portion 82 is
composed of an inwardly extending portion 83, a distally extending
portion 84, an outwardly extending portion 85, a proximally
extending portion 86, and an inwardly extending portion 87.
[0054] In the catheter 5, the degree of engagement of the second
bonding portion 50e is higher than the degree of engagement of the
first bonding portion 50d (more specifically, the engaging force
between the second inner layer protruding portion 12e and the
second outer layer protruding portion 82 of the second bonding
portion 50e is stronger than the engaging force between the first
inner layer protruding portion 12d and the first outer layer
protruding portion 42d of the first bonding portion 50d). When the
catheter 5 is inserted into a peripheral section of a blood vessel,
a bile duct, a pancreatic duct, or the like, the distal side E of
the catheter 5 bends to a great extent to follow the curve of the
vessel, and stress becomes concentrated at the second bonding
portion 50e where the second outer layer 80 made of a flexible
resin is bonded to the inner layer 10d. However, the high degree of
engagement between the second inner layer protruding portion 12e
and the second outer layer protruding portion 82 of the second
bonding portion 50e (more specifically, the strong engaging force
between the second inner layer protruding portion 12e and the
second outer layer protruding portion 82), as well as the enlarged
area across which the second outer layer 80 and the inner layer 10d
are bonded to each other in the gap 25 of the reinforcing layer
(coil body) 30, strengthen the bond between the second outer layer
80 and the inner layer 10d, which can reduce the probability that
the second outer layer 80 made of a flexible resin will come off
the inner layer 10d.
[0055] The configuration of the reinforcing layer (coil body) 30 of
the catheter 5 may be modified in the following ways: (i) as in the
catheter 2 shown in FIG. 4, an inward surface of the coil body 30
as the reinforcing layer may be buried in the inner layer 10d and
an outward surface of the coil body 30 as the reinforcing layer may
be buried in the first outer layer 40d and the second outer layer
80; or (ii) as in the catheter 3 shown in FIG. 5, the coil body 30
as the reinforcing layer may be disposed on the outer surface of
the inner layer 10d. In the catheter 5, the reinforcing layer (coil
body) 30 may be replaced by the reinforcing layer (braid) 35, as in
the catheter 4 shown in FIG. 7.
[0056] Next, referring to FIG. 9 and FIG. 10, a balloon catheter 6
according to the disclosed embodiments is described below. FIG. 10
is an expanded view of part F shown in FIG. 9. The balloon catheter
6 is, for example, a therapeutic balloon catheter used for dilating
a stenosis for curative purposes.
[0057] As shown in FIG. 9, the balloon catheter 6 comprises a
balloon 90, a tip 100, an outer shaft 110, an inner shaft 60a, a
reinforcing member 120, and a connector 130.
[0058] The balloon 90 for dilating a stenosis is made of a resin
component. A distal end of the balloon 90 is bonded to a distal end
of the inner shaft 60a and the tip 100. A proximal end of the
balloon 90 is bonded a the distal end of the outer shaft 110.
[0059] The outer shaft 110 is a tubular component constituting an
expandable lumen 116, which feeds liquid such as a contrast medium
and physiological saline for expanding the balloon 90. The outer
shaft 110 is composed of, from the distal end, an outer-shaft
distal end 111, a guidewire port 113, an outer-shaft middle portion
115, and an outer-shaft proximal end 117. Each of the outer-shaft
distal end 111 and the outer-shaft middle portion 115 is a tube
made of a resin such as a polyamide, a polyamide elastomer, a
polyolefin, a polyester, or a polyester elastomer. The guidewire
port 113 is where the outer-shaft distal end 111, the outer-shaft
middle portion 115, and the inner shaft 60a are bonded to each
other.
[0060] The outer-shaft distal end 111 accommodates the inner shaft
60a inserted thereinto. Between the outer-shaft distal end 111 and
the inner shaft 60a, the expandable lumen 116 described above is
formed.
[0061] The outer-shaft proximal end 117 is a tubular metal
component, called a hypotube. A distal end of the outer-shaft
proximal end 117 is inserted into and bonded to a proximal end of
the outer-shaft middle portion 115. A proximal end of the
outer-shaft proximal end 117 has the connector 130 attached
thereto. Liquid for expanding the balloon 90 such as a contrast
medium and physiological saline can be fed from an indeflator (not
shown) attachable to the connector 130, and travels through the
expandable lumen 116 to reach and expand the balloon 90. The
material constituting the outer-shaft proximal end 117 is not
particularly limited and may be a super-elastic alloy such as
stainless steel (SUS302, SUS304) or a Ni--Ti alloy.
[0062] Accommodated in the interior of the inner shaft 60a is a
guidewire lumen 62 into which a guidewire is inserted. A proximal
end of the inner shaft 60a is bonded to the guidewire port 113 of
the outer shaft 110 to form a proximal end-side guidewire port 134.
Through the proximal end-side guidewire port 134, a handler can
replace a guidewire.
[0063] The tip 100 is bonded to the distal end of the inner shaft
60a and the distal end of the balloon 90. The tip 100 is made of a
flexible resin. The material thereof is not particularly limited
and may be a polyurethane or a polyurethane elastomer, for example.
The tip 100 has a distal end-side guidewire port 133 on the distal
end thereof.
[0064] The reinforcing member 120 is bonded to an inner
circumference of a distal end of the outer-shaft proximal end 117.
The reinforcing member 120 is a tapered metal wire that has a
circular cross section tapered toward the distal end. The material
of the reinforcing member 120 is not particularly limited and may
be a super-elastic alloy such as stainless steel (SUS304) or a
Ni--Ti alloy. The reinforcing member 120 extends through the
outer-shaft middle portion 115 and then through the guidewire port
113 to reach the outer-shaft distal end 111. The reinforcing member
120 has a pushing member 122 that can come into contact with the
guidewire port 113.
[0065] The interior of the balloon 90 accommodates two markers 105
attached to an outer circumference of the inner shaft 60a. This
configuration allows a handler such as a doctor to keep track of
the exact location of the balloon 90 during coronary angiography,
leading to reliable dilation of a stenosis.
[0066] As shown in FIG. 10, the inner shaft 60a comprises an inner
layer 10e having the reinforcing layer (coil body) 30 disposed
therein. The balloon 90 is bonded to the outer circumference of the
inner shaft 60a and covers the reinforcing layer (coil body)
30.
[0067] In the portion where the inner shaft 60a is bonded to the
balloon 90, a bonding portion 50f is disposed in the gap 25b of the
reinforcing layer (coil body) 30. In the bonding portion 50f, an
inner layer protruding portion 12f of the inner layer 10e extends
into the balloon 90 and is engaged with a balloon protruding
portion 92 of the balloon 90 that extends into the inner layer
10e.
[0068] The inner layer protruding portion 12f is composed of a
proximally extending portion 13f, an inwardly extending portion
14f, and a distally extending portion 15f. The balloon protruding
portion 92 is composed of an inwardly extending portion 93, a
distally extending portion 94, an outwardly extending portion 95,
and a proximally extending portion 96.
[0069] The bonding portion 50f enlarges the area across which the
balloon 90 and the inner layer 10e are bonded to each other within
the gap 25b of the reinforcing layer (coil body) 30, leading to a
strengthened bond between the balloon 90 and the inner layer 10e.
The balloon 90 is anchored in the reinforcing layer (coil body) 30,
which reduces the probability that the balloon 90 will come off the
inner layer 10e when the balloon catheter 6 bends, which causes the
balloon 90 to be pulled in the axial direction (in the distal
direction and in the proximal direction).
[0070] The engagement between the inner layer protruding portion
12f and the balloon protruding portion 92 of the bonding portion
50f can reduce the probability that the balloon 90 will come off
the inner layer 10e when the balloon 90 is expanded radially
(outwardly). In addition, the engagement between the inner layer
protruding portion 12f and the balloon protruding portion 92 can
allow a reduction in the thickness of the balloon 90 while
maintaining the strength of the bond between the balloon 90 and the
inner layer 10e, facilitating insertion of the balloon catheter 6
into a blood vessel, a bile duct, a pancreatic duct, or the
like.
[0071] The inner shaft 60a of the balloon catheter 6 shown in FIG.
9 and FIG. 10 may be a combination of the inner layer 10, 10a, 10b,
10c, 10d of the catheter 1 to 5 and the reinforcing layer (coil
body) 30 or the reinforcing layer (braid) 35 disposed in the inner
layer 10, 10c, 10d or on the outer circumference of the inner layer
10a, 10b.
[0072] The first bonding portion 50, 50a, 50b, 50c, 50d of the
catheter 1 to 5 may have any shape provided that the first inner
layer protruding portion 12, 12a, 12b, 12c, 12d and the first outer
layer protruding portion 42, 42a, 42b, 42c are engaged with each
other therein. The second bonding portion 50e of the catheter 5 may
also have any shape provided that the second inner layer protruding
portion 12e and the second outer layer protruding portion 82 are
engaged with each other therein. In addition, the bonding portion
50f of the balloon catheter 6 may also have any shape provided that
the inner layer protruding portion 12f and the balloon protruding
portion 92 are engaged with each other therein.
[0073] In a catheter 7 according to the disclosed embodiments,
which is illustrated in FIG. 11, a first bonding portion 50g is
disposed in a gap 25c of the reinforcing layer (coil body) 30. At
the first bonding portion 50g, first inner layer protruding
portions 12g, 12h of an inner layer 10f extend into a first outer
layer 40e and are engaged with a first outer layer protruding
portion 42e of the first outer layer 40e that extends into the
inner layer 10f.
[0074] The first inner layer protruding portion 12g is composed of
a distally extending portion 13g, an inwardly extending portion
14g, and a proximally extending portion 15g. The first inner layer
protruding portion 12h is composed of a proximally extending
portion 13h, an inwardly extending portion 14h, and a distally
extending portion 15h. The first outer layer protruding portion 42e
is composed of an inwardly extending portion 43e that bifurcates
into an axially extending portion 44e that extends in both the
distal direction and the proximal direction, two outwardly
extending portions 45e extending outwardly from either end of the
axially extending portion 44e (i.e., a proximal outwardly extending
portion and a distal outwardly extending portion), and two terminal
extending portions 46e extending distally from the proximal
outwardly extending portion and proximally from the distal
outwardly extending portion, respectively.
[0075] In a catheter 8 according to the disclosed embodiments,
which is illustrated in FIG. 12 a first bonding portion 50h is
disposed in a gap 25d in the reinforcing layer (coil body) 30. At
the first bonding portion 50h, first inner layer protruding
portions 12j, 12k of an inner layer 10g extend into a first outer
layer 40f and are engaged with a first outer layer protruding
portion 42f of the first outer layer 40f that extends into the
inner layer 10g.
[0076] The first inner layer protruding portion 12j is composed of
a distally extending portion 13j and an inwardly extending portion
14j. The first inner layer protruding portion 12k is composed of a
proximally extending portion 13k and an inwardly extending portion
14k. The first outer layer protruding portion 42f is composed of an
inwardly extending portion 43f that bifurcates into an axially
extending portion 44f that extends in both the distal direction and
the proximal direction, and two outwardly extending portions 45f
extending outwardly from either end of the axially extending
portion 44f (i.e., a proximal outwardly extending portion and a
distal outwardly extending portion).
[0077] The reinforcing layer described above with respect to
catheters 1 to 5, 7, and 8 and the balloon catheter 6 is either the
coil body 30 or the braid 35, but the reinforcing layer is not
limited to this configuration. For example, the reinforcing layer
of any of the catheters 1 to 5, 7, and 8 and the balloon catheter 6
may be a hypotube (metal tube) having a helical slit serving as the
gap.
* * * * *